Shingle-cutting knife



March 25, 1930. D. STINGER 1,751,563

SHINGLE CUTTING KNIFE Filed 001;. 22, 1925 INVENTOR DAN/EL 5T/NGER BY '7w f ATTORNEY Patented Mar. 25, 1930 UNITED STATES PATENT OFFICE DANIEL STINGER, OF PHILADELPHIA, I EENNSYLVANIA, ASSIGNOR TO THE BARRETT COMPANY, A CORPORATION OF NEW JERSEY SHIN GLE-CUTTING KNIFE Application filed October 22, 1925. Serial No. 64.082.

This invention relates to knives for severing a traveling web of paper'and more particularly to shingle cutting machine knives.

Heretofore, knives of the type necessary to cut shingles from a strip of asphalt and tar impregnated felt have been inserted in recesses in the cutting roll perpendicular to a tangent to the roll and have been held in place by any suitable wedging means. In order to accomplish the purpose for which they are intended,the knife must necessarily protrude from the surface of the roll some little distance, sometimes as much as an inch or more. Prepared roofing material. because of its tarry impregnation, is very difficult to cut causing severe strain to be exerted upon the knives and with the old type of knife, breakage was constantly occurring. In some instances this has been found to be a very notable factor in the'cost of production.

It is among the objects of this invention to provide a knife with which a minimum amount of breakage will occur and with which, at the same time, a clean cut shingle will also be obtained. I

This invention will best be understood from the following description and accompanying drawings made a part hereof.

In the drawings in which like reference characters refer to like parts,

Fig. 1 is a plan view of my improved knife structure as mounted upon a. portion of a cutting roll,

Fig. 2 is a sectional view along the line 22 of Fig. 1 and shows also the platen roll in position. I

In the type of machine in which this kind of knife is used the cutting roll (1) rotates synchronously with a platen roll (2) (in the direction of the arrow) so that the sheet of roofing material (3) may be fed between the rolls. Roofing elements will thus be cut into hexagonal, octagonal or rectangular strips, in accordance with the predetermined arrangement or setting of the knives.

In thecircumferential surface of roll (1) is formed a longitudinal recess (4) within the rear portion of which is partially located the knife (5). In front of this knife and snugly fitting into the recess (4) is placed the wedge block (6), which is adapted to be tightened and held in place by'the shouldered machine screws (7) threaded into the body of the roll.

To the rear of and in longitudinal alignment with the recess (4) is another recess (8) which extends substantially the entire width of the knife (5). In this recess is located the back stop (9) which is substantially the same width as the knife (5). The back stop (9) is held securely in position by the machine screws (11). It is to be noted that the rear wall of the back stop (9) abuts the rear wall of the recess (8) and that because of the fillet (12) upon the upper forward portion of the back stop and engagement of the back stop with substantially the entire rear portion of the knife protruding from the surface of the roll, the knife will not be subject to breakage (except in'the case of defective materials) as'the cutting roll is rotated and the knife contacts with and severs the roofing material to be cut.

Furthermore, because of the fillet (12) the cutting edge of the knife is reinforced without interfering with the efiiciency of the knife in severing the material to be cut.

Thus by my invention I have reduced breakage of cutting knives to a minimum, as a well as made it possible to use a knife of cheaper material, whereas heretofore it was required that the knife be constructed of the very best tool steel available in order to stand up in service with any satisfaction whatsoever.

\Vhat I claim as new and desire to be secured by Letters Patent of the United States 1. A cutting roll, a knife located in a longitudinal recess-in the circumferential surface .of'said roll and protruding therefrom and a back stop secured to the roll in contact with the protruding portion of the knife.

2. A cutting roll, a knife radially located in a longitudinal recess in the circumferential surface of the roll with its cutting edge protruding beyond the surface of said roll and a back stop secured to the roll in longitudinal alignment and in contact with the protruding portion of the knife.

3. A cutting roll, a knife located in a lon itudinal recess in the circumferential sur ace of said roll and protruding therefrom and a back stop secured to the roll in contact with the protruding portion of the knife, the end of the back stop which contacts with the knife being thicker than its opposite end.

4. A cutting roll, a knife located in a recess in said roll and protruding therefrom, and a back stop secured to the roll in contact with the protruding portion of the knife, the end of the back stop which contacts with the knife being thickened by a fillet.

5. A cutting roll, a knife located in a recess in said roll and protruding therefrom and a back stop located in another recess in said roll and secured to the roll in contact with substantially the entire rear side of the protruding portion of the knife.

6. A cutting roll, a longitudinal recess in the peripheral face of said cutting roll substantially parallel with the axis of the roll,

a knife and knife locking means in said recess, the knife protruding from said roll, and a back-stop secured to the roll in contact with substantially the entire rear side of the protruding portion of the knife.

7. A cutting roll, a longitudinal recess in the peripheral face of said cutting roll substantially parallel with the axis of the roll, a knife and knife locking means in said recess, the cutting edge of said knife being in line with the rear face of said recess and the knife protruding from the roll, and a backstop secured to the roll in contact with the rear side of the protruding portion of the knife, the end of the back-stop which contacts with the knife being thickened by a fillet which substantially merges into the cuttinlg edge of the knife.

n testimony whereof I aflix my signature.

DANIEL STIN GER. 

